| json_read | Write and read R values as JSON |
| json_read_str | Write and read R values as JSON |
| json_revive | Persist a class the default rule does not fit |
| json_state | Persist a class the default rule does not fit |
| json_write | Write and read R values as JSON |
| json_write_str | Write and read R values as JSON |
| r6_restore | Record an 'R6' instance as the bindings it holds |
| r6_state | Record an 'R6' instance as the bindings it holds |